Coee drill



I h/A/AIAAANIQBig M w a J U M '1 MW 6 May 31, 1932. R. B. GRAINGER ORE DRILL Filed Jan. 3, 1

' whereby the threaded Patented May 31, 1932 UNITED (STATES REID B. GRAIN'GER, 0F BEACH,

CALIFORNIA, ASSIGNOR TO ELLIOTT DRILLING COMPANY, A CORPORATION OF CALIFORNIA CORE - Application filed January This invention relates to the art of core drilling, and deals with core drills which are known as a double barrel core drill.

Double barrel core drills in common use comprise in part an outer barrel, an inner barrel, a cutter body, and a cutting head, with means for mounting the inner barrel either in the outer barrel or in the cutter body; such means heretofore comprising screw-threaded connections.

The present invention departs from the usual construction, and embodies'an improve ment in the structural arrangement *ofcore drills of thecharacter described, for mountin the inner core barrel in the cutting head.

11 practice, core drills sometimes have inner barrels extending upwardly for a distance of 20 feet, which barrels are screwthreadedly supported at their lower ends and unsupported at their upper ends, and, consequently, have a tendency to vibrate and loosen the screw-threaded connection during the drilling operation. This results not only in tending to destroy the corewithin the barrel, but eventually ruins the threaded connection. It is, therefore, a primary object of this invention to provide a mounting for an inner barrel in acore drill of the type described, connection between the inner barrel and its supporting structure is eliminated. As a means to this end, I provide an inner barrel loosely mounted in a cutting head and held therein by means of a locking ring held in place by a sub which connects the drill pipe with the cutting head. Under this arrangement, the threaded connection between the inner barrel and the head is done away with, and, consequently, the disadvantages of screw-threaded connections. are eliminated. Also,\under this arrangement, the barrel is free to rotate with respect to the cutting head, and may remain stationary with the core, depending mainly upon the frictional contact of the core with the core arrel. Accordingly, it becomes a further object to remain stationary with respect to the rotating outer barrel by virtue of frictional engagement of the core within the inner barrel.

It is anotherobject ofthis invention to provide an inner barrel which may DRILL 8, 1931. Serial No. 506,395.

obtain a larger core relative to the diameter d of the cutting by the structure and arrangement of'parts, whereby some of the parts heretofore deemed indispensable are eliminated, with the consequent reduction in the number of screwthreaded joints, and a resulting increase in the size of the core opening. In addition, the general tendency in core drilling has been lately to bring the outlets" of the circulating fluid as near the zone of cutting as possible. By virtue of the arrangement of parts in my core drill, I am enabled to do this. Consequently, it becomes another object of this invention to provide a core drill wherein the circulating fluid outlets are substantially in the zone of cutting.

head. This is brought about In rotatably locking the inner core barrel in place, I employ a locking ring, and form said ring fluid. In the preferred embodiment of my invention, I use this locking ring as a floating member so that in case the ring becomes ineffective, due to wearing away-from friction or by the cutting action of the circulating fluid, it may be readily replaced. Accordingly, it becomes another object of this lIlVQIltlOH to provide in a core drill of the.

character described a locking ring adapted to lock theinner core barrel in place, said locking ring having fluid passages therethrough. y

Ordinarily, double barrel core drills include a drillbody or-cutter body inter osed between the sub and the cutter head. 11 my improved core drill, the drill body is dispensed with and the cutter head is mounted directly upon the sub with the consequent reduction in the number of parts. Anoteworthy feature which results from the-arrangement of parts in my drill is the ease with which a core catcher may be rotatably with passages for the circulating mounted therein. Other features such as the elimination of carefully machined joints and threaded connections, will be best. appresection on line 2-2 of Fig. 1,

ciated from the following description with gig. 3 is a section on line 3-3 of Fig. 1; an

Fig. is a fragmentary vertical section of another form of my invention. Referring to the drawings, and particularly to Fig. 1, I have shown a core drill of the double barrel type. Ordinarily, core drills of this type, as commonly used, comprise an inner and an outer barrel, a cutter body, a cutter head, and a sub connecting the cutter body to the drill pipe. As before stated, my invention reduces the number of parts employed in a double barrel core drill of this character and eliminates the cutter body by utilizing the drillpipe 1i and the. sub 12 as the outer core barrel; the inner core barrel 13 being rotatably mounted upon the cutter head 14 and heldtherein by looking means to be more fully described hereinafter, and the cutter head 1a being directly I threaded to the sub 12.

-tional manner,

of the core passage As shown, the sub 12 is screw-threadedly mounted on the drill pipe 11 in the convenand the cutter head is" in turn is screw-threadedly mounted in the sub 12'. The cutter head 14 may be equipped with cutterd blades 15' which may be of'any shape and size, and may also have annular cutting teeth 16 which function as a core trimming means, A core passage 17 extends through the cutter head 14 from the core trimming teeth 16, said passage being enlarged and forming a: shoulder 18 a short distance above the cutting teeth 16. Another enlargement 17 is made above the first mentioned enlargement, and forms a shoulder 19. The upper end of the cutter head, as before stated, is screw threadedly joined to tltiaeliub 12 by means of screw threads, shown a 1 Means is providedfor rotatably molint- I ing the inner core barrel 13in the cutter head 14, and preferably consists of a beariIig ring 20 mounted on the exterior of the inner barrel near the lower end thereof, said ring being of any suitable wearing material, such as bronze, and having a lower shoulder 21 adapted to seat upon the shoulder 19in the cutter head. The ring 20 is also formed withan upper shoulder 22 upon which is seated a floating lockingring 23. 7 Under this arrangement, the floating r ng is readily replaceable and, if desirable, may be made of material such as hard rubber, and, if necessary, may be replaced after'each core-taking operation with a minimum cost.

The means for rotatably holding the inner barrel 13, in the cutter head 14, comprises ,a shoulder 24 formed by the lower end of the sub 12 adapted to slidablv engage the floating ring 23; it being understood that thedrill pipe 11 and the sub 12 are provided with a conventionally shouldered threaded connection, such as shown at 1 1.

. Asshown in Fig.2, the ring 23 is pro- -the core opening 17 however, this arrangement, the floating ring shown in vided with a plurality of fluid passages 25 for passing the circulating fluid, and the cutter head 14 is provided with passages 26 that communicate with an annular chamber 27 formed below the ring 23. The annular chamber 27 is a result of extending the ring 20 only partially into the enlarged bore of which forms the shoulder 19. Thisarrangement of fluid passages will be appreciated as bringing the circulating fluid directly into the zone of cutting.

A core catcher ring 28 having fingers 28' mounted thereon is mounted on the shoulder 18, and is held in rotatable engagement there in by stopping the lower end of the core barrel 13 short of pressure contact with the ring 28. The upper end of the core barrel may be provided withany suitable check valve designated A, for preventing the cir culating fluid flowing downwardly through the core barrel.

The operation of the drill is similar. to any core drill, but it is obvious that the labor of assembling the drill and operating the drill is considerably decreased due to the simplicit y the reduction in the number of parts.

In Fig. 4, I have shown another form of the invention. In this view, the same cutter head-14 is employed and'is connected to the sub 12 in identically thesame manner as shown in'Fig. 1. The inner barrel 13, however, in this instance, is provided with a ring 34 of sufiicient diameter to engage the lower end 24 of the sub 12. The ring 34 is secured to the inner barrel 13 by means such as welding, shown at 35, or it may be an.integral part of the. core barrel. It is, formed with fluid passages 36. In

Fug. 1 is eliminated with the consequent further reduction in the number of parts. The manner of assembling would be the same, and the device would function identically with the arrangement shown in Fig. 1.

I Although I have {shown preferred forms of my device, I am aware that other modifiand the arrangement of parts, and I cations may be resorted to in the process of manufacture which would in no wise alter the basic structure of my device. Conseguentlyfl reservethe right to all such modications and refinements which, under the doctrine of equivalents, come within the S00 of the specification and the purview of t e appended claims.

I claim as my invention: I

1. In a core drill: a cutter headhaving a core-receiving opening therethrough, said opening having an annularshoulder theren; a core receiving barrel loosely mounted in said opening and having an external shoul- 'der adapted to bear upon said annular shoulder; and floating means engageable with sald external shoulder for rotatably locking said barrel in said opening.

\ ring to rotatably hold adapted to engage said external shoulder;

and means for engaging said locking ring to rotatably hold said barrel in said opening.

a core-receiving opening therethrough, sai opening having anannular shoulder near the upper end thereof; a core-receiving barrel loosely mounted in said opening and having an external shoulder adapted to bear upon said annular shoulder; a locking ring adapt ed to engage said external shoulder; and means for engaging said locking ring to rotatably hold said barrel in said opening, said locking ring having fluid passages therethrough communicating with fluid'passages in said cutter head. "i

4.-In a core drill: a cutter head having a core-receiving opening therethrough, said opening havin an annular recess at the u per end thereo? forming an inwardly extending annular shoulder; a core-receiving barrel loosely mounted in said core-receiving opening; an outwardly extending annular shoulder on said barrel adapted to seat upon said inwardly extending shoulder, said outwardly extending shoulder forming an annular space with the wall of said recess; a looking ring adapted to bear upon said outwardly extending shoulder, said lockin ring having passages communicating with said annular space and said cutter'head having passages communicating with said annular space; and means for engaging said locking said barrel in said cutter head.

5. In a core drill: a sub; a cutter head mounted on said sub; a core-receiving barrel loosely mounted in said head; and means engageable by said sub for rotatably locking said barrel in said head, said means including a floating locking ring having fluid passages therethrough. v

6. In a double barrel core drill: an outer barrel; a sub threaded to the lower end of the outer barrel; a cutter head threaded to the lower end of said sub; an innerbarrel in the outer barrel; means on the inner barrel extending between the sub and cutter head for loosely supporting the inner barrel, said means on the inner barrel comprising an outwardly extending ring on the inner barrel; and a loose ring associated with the ring on the inner barrel, the loose ring being of larger diameter than the ring on the inner barrel and having fiuid passages therethrough, said passages in the loose ring com- 3. In a core drill: a cutter head having v municatin with the space between the inner and outer iarrels and with fluid outlet pas-V sages formed in said cutter head.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 26 day of Dec, 1930.

REID B. GRAINGER. 

